1. Field of the Invention
The present invention relates to a tire pressure gauge. In particular, the invention relates to a tire pressure gauge that digitally displays and aurally outputs the value of pressure measured by it.
2. Description of the Related Art
There are a variety of conventional tire pressure gauges that digitally display the values of pressure measured by them. A prior art tire pressure gauge displays and aurally outputs the value of pressure measured by it. For example, Japanese Utility Model Registration No. 3,068,608 and U.S. Pat. No. 6,385,554 may be referred to.
However, there has been no tire pressure gauge capable of measuring the tire pressure of a bicycle, a car or the like, digitally displaying the measured value in predetermined units of pressure and aurally outputting the value in different languages.
In general, the tire pressure of bicycles is high and ranges from about 1 kg/cm2 to about 8 kg/cm2, while the tire pressure of cars is low and about a half of that of bicycles. The air valves particularly of bicycle tires differ in size between the American and French types and among different countries. Accordingly, various tire pressure gauges are required for different valve sizes and different pressure ranges.
Various types of bicycle tires and car tires have different ranges of optimum pressure. In general, if a vehicle runs with its tires low in pressure, both sides of the outer peripheral surface of each tire wear out due to their friction against the road surface. This affects the life of the tire. In particular, if a car runs at high speed with its tires low in pressure, they heat up to dangerous temperatures. If a vehicle runs with its tires too high in pressure, only the midsection of the peripheral surface of each tire contacts with the road surface and abnormally wears out.
Accordingly, different ranges of optimum tire pressure are set for bicycles and cars, which are vehicles having tires. The tire pressure of each vehicle having tires needs to be checked at regular intervals according to the condition under which the vehicle is used.
Recent industrial globalization causes many cars and bicycles made in foreign countries to be imported. Some tire pressure gauges are imported, and others are exported. In general, tire pressure gauges for use in each country display values of tire pressure in the units of pressure used there, and aurally output them in the language or one of the languages of the country. The tire pressure gauges that aurally output values of pressure in only one language are inconvenient in a country where two or more languages are spoken.